Sound-control construction



Oct; 16, 1928. 1,687,566

L. HUNT v scum) CONTROL CONSTRUCTION Filed July 2, 1926 Patented Get.16, 1928.

UNITED STATES LEIGH HUNT, OF CHICAGO, ILLINOIS, ASSIGIIOR T0 ORO-TGNT,COMPANY, OF CHICAGO,

orrics- ILLINOIS, A CORPORATION CF ILLINOIS.

SOUND-CONTROL CONSTRUCTION.

App1ication filed July 2,

ter adapted to improve the quality and control the volume of sound.

Constructions of this character are particularly adapted for use inconnection with phonographic reproducing mechanisms but are also capableof use with other forms of sound reproducers, such, for example, asradio loud speaking units. p I

'It has been found that to improve the quality of sound and to providethe proper amplification, it is essential that a relatively long path beprovided for the sound waves. The expansion of the cross sectional areaof the sound passages should be gradual and it has been also found thatdivision and reflection of the sound waves are important fac tors inimproving the fidelity of reproduction. The length and size of the soundchambers must be held within practical limits due to the sizes it iscommercially practical to construct amplifiers of this character.

It is an object of the present invention to provide means forcontrolling the amplification of sound and for providing a variablecontrol of the passage areas and relation of reflecting surfaces.

It is an additional object to provide a construction of this characterwhich is simple in design and adapted to be located in a relativelysmall space.

It isa further object to provide a construction of this character inwhich arelatively long path of sound travel is provided. and in whichthe sound waves are divided and separately reflected.

Other and further objects will appear as the description proceeds. I

Ihave illustrated one preferred embodiment of my invention in theaccompanying drawings, in which Figure 1 is a front View of the withparts broken away; and c Figure 2 is a vertical section taken on line2-2 of Figure 1. e r

The construction as shown is supported in a phonograph cabinet orsimilar housing 11, having a sound discharge opening 12, and

construction 1926. serial No. 120,006.

with its upper end closed by the motor board or similar member 13. Thephonograph operating mechanism has not been shown, as this forms nopartof the present invention. It will be understood that the phonographtone arm will be so located as to discharge sound into the throatpassage 14 in the throat member 15. Sound may be discharged into thethroat passage also from a radio loud speaking unit or other source ofsound, and any desired connecting means may be provided. The throatmember 15 is supported from the motor boardl3 by the bolt 16 engagingthe lug 17 The sound chamber 18 is supported in the cabinet by themembers 19 and 20, and is formed with the open side 21, the flaring topand bottom walls 22 and 23, and the parallel sides 24 and 25. The lowerend 2601 the throat member 15 extends through the rear wall 27 of thesound chamber 18. This rear wall 27 is provided with the transverselyextending ridge 28. The pointof the ridge extends on the plane of themiddle of the 7 lower open end of the throat member 26. As shown inFigure 1, the lower end of this throat is substantially rectangular incross sect-ion and is elongated horizontally.

The reflecting member 29 is supported upon the slides 30 which runbetween the guide members 31 carried by the inner faces of the walls 24and 25 of the amplifying chamber. The reflecting member 29 has the Iflaring top and bottom walls 32 and 33, and has parallel side walls. Theside walls are provided with the notches 34L which are similar in formto the ridge 28 formed on the inner wall of the sound amplifyingchamber. The inner wall 43 of the reflecting memher is provided with thetransversely extendingridge 35 which extends in the same plane as theridge 28 and is directed opposite to that ridge. The side edges of thelower end 26 of the throat member are provided with thereto. The link 41is pivotally secured to the free end of the arm 40 and to the member 42which is secured to the reflecting member 29.

The lower portion 4st of the inner wall &3 of the reflecting member ishingedly connect-ed to the lined upper portion by the hinge 4:5. The rodL6 passing through the hinge has one end keyed to the arm at, the lowerend of which is connected to the lower part of the member a l. The otherend of this rod has connected thereto a flexible shaft l8, the upper endof which is controlled by knob 49. By rotating this knob the member 42%may be rotated about the hinge to permit direct passage of a portion ofthe sound if desired. A portion 50 of the ridge 35 is carried by themember 4.4.

Sound waves passing down the throat 14 will be directed against theridge and will be divided by this ridge and reflected by its lateralsurfaces against the flaring walls 32 and of the reflecting member. Thesound waves will thus be directed against the ric go 28 and also theinner wall 27 of the sound amplifying chamber. From this ridgeand wallthe waves are reflected downwardly past the edges of the reflectingmember and out through the open side of the amplifying chamber. Thereflecting member may be moved toward and away from the throat and innerwall of the amplifying chamber by rotating the control knob 38. With thememher in the full line position of Figure 2, the sound. passage area isgreatly reduced and the tone of the sound is rendered low and full. Withthe member moved outwardly the pitch of the tone is raised and it ismade more brilliant. The volume may be controlled as well as the pitchand quality by moving the member out and in as desired. It will beunderstood also that variation of the location of the reflecting memberwill vary both the length and formation of the sound as well the area ofsuch passages, and the relation of the reflecting surfaces, and willaccordingly control not only the sound volume but also the tone andquality of the sound.

The swinging member 44. constitutes another volume and tone control, andwhen open this permits the direct discharge of some of the sound thusretaining the brilliancy of the higher tones while the reflection of theremainder of the sound retains the full rich tones of the lower notes.

It is to be understood that the specific showing of the parts herein isfor the purpose of illustration only and their proportions and relationsand the mechanical means for operating them may be varied within thespirit and scope of the appended-claims withoutdeparting from myinvention.

I claim:

1. Sound control construction comprising an amplifying chamber having anopen side, a threat passage entering the side opposite the open side,and a reflecting member positioned in the chamber opposite the throat,said reflecting member having a ridge extending across the face oppositethe throat, said ridge serving to divide the sound.

2. Sound control construction comprising an amplifying chamber having anopen side, a throat passage entering the side opposite the open side, areflecting member positioned in the chamber opposite the throat, saidreflecting member having a ridge extending across the face opposite thethroat, said ridge serving to divide the sound, and a ridge formed inthe face of the sound chamber through which the throat enters, saidridge serving to divide the sound reflected against said face by thereflecting member.

8. Sound control construction comprising an amplifying chamber having anopen side, a throat passage entering the side opposite the open side, a.reflecting member positioned in the chamber opposite the throat, saidreflecting member having a ridge extending across the face opposite thethroat, said ridge serving to divide the sound, and a ridge formed inthe face of the sound chamber through which the throat enters, saidridge serving to divide the sound reflected against said face by thereflecting member, the reflecting member being movable toward and awayfrom the throat to control the volume and quality of sound.

4:. Sound control construction comprising a throat member, a reflectingmember positioned opposite the throat, a portion of the reflectingmember being movable independently of the remainder of the reflectingmember whereby it may be moved out of the path of sound issuing from thethroat. v

5. Sound controlconstruction comprising an amplifyin; chamber having anopen side, a throat passage entering the side opposite the open side,and a reflecting member positioned in the chamber opposite the throat,the reflecting member being movable toward and away from the throat tocontrol the volume and quality of sound, a portion of the reflectingmember being movable whereby it may be moved out of the path of soundissuing from the throat.

6. Sound control construction comprising an amplifying chamber having anopen side, a throat passage entering the side opposite the open side,and a reflecting member positioned in the chamber opposite the throat,said reflecting member having a ridge extending across the face oppositethe throat, said ridge serving to, divide the sound, the throat memberhaving notches in its edge whereby the ridge on the reflecting membermay extend into the throat.

7. Sound control construction comprising an amplifying chamber having anopen side,

a throat passage entering the side opposite through which the throatenters, said ridge the open side, a reflecting member positioned servingto divide the sound reflected against in the chamber opposite thethroat, said resaid face by the reflecting member, the two 10 fleetingmember having a ridge extending ridges extending in the same plane.

5 across the'face opposite the throatQsaid ridge Signed at Chicago,I11in0is,this 26th day serving to divide the sound, and a ridge of June,1926. formed in the face of the sound chamber LEIGH HUNT.

